1. Explain the principle of ultrasound scanning and how it can be used to produce 2D images of tissues e.g. baby's tissue in a mother's womb. 2. Calculate the fraction of reflected ultrasound energy when ultrasound waves cross from soft tissue into fat if the acoustic impedance for soft tissue is 1.60 x 106 kg m² s and for fat has the value 1.40 x 106 kg m-² s-1.

You arrive at a home to find a young man deceased in his bedroom at his parents home. His parents state he came home from work at about 5pm the night before then went out some clubs and came home in the early morning. In his pants you find 700 in cash and an atm receipt from that night time stamped 7:30 pm withdrawing $40.00 dollars from his bank. What various scenarios can explain findings ? Detail at least two possible scenarios for what might have happened include details including 1. Where he might have been 2. Who he might have been with 3. What activities he might have been engaged in  4.how the evidence you have found might support/ negate your theory

A train leaves the train station at 11:30 am. It travels at a speed of 9 mph. Another train leaves the train station at 12:30 pm. It travels at a speed of 12 mph. How long will i take the second train to reach the first train. I left the 12:30 pm out the earlier question. The earlier time was something like + 0.50t?

Bob has just finished climbing a sheer cliff above a level beach and wants to figure out how high he climbed. All he has to use is a baseball, a stopwatch, and a friend on the ground below with a long measuring tape. Bob is a pitcher and knows that the fastest he can throw the ball is about ?0=34.1 m/s.v0=34.1 m/s. Bob starts the stopwatch as he throws the ball, with no way to measure the ball's initial trajectory, and watches carefully. The ball rises and then falls, and after ?1=0.910 st1=0.910 s the ball is once again level with Bob. Bob cannot see well enough to time when the ball hits the ground. Bob's friend then measures that the ball hit the ground ?=123 mx=123 m from the base of the cliff. How high above the beach was the ball when it was thrown?